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From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>,
	Kees Cook <keescook@chromium.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Kristina Martsenko <kristina.martsenko@arm.com>,
	Dave Martin <Dave.Martin@arm.com>,
	Mark Brown <broonie@kernel.org>,
	James Morse <james.morse@arm.com>,
	Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>,
	Amit Daniel Kachhap <amit.kachhap@arm.com>,
	Vincenzo Frascino <Vincenzo.Frascino@arm.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH v5 12/17] arm64: unwind: strip PAC from kernel addresses
Date: Mon, 17 Feb 2020 14:57:43 +0530	[thread overview]
Message-ID: <1581931668-11559-13-git-send-email-amit.kachhap@arm.com> (raw)
In-Reply-To: <1581931668-11559-1-git-send-email-amit.kachhap@arm.com>

From: Mark Rutland <mark.rutland@arm.com>

When we enable pointer authentication in the kernel, LR values saved to
the stack will have a PAC which we must strip in order to retrieve the
real return address.

Strip PACs when unwinding the stack in order to account for this.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Re-position ptrauth_strip_insn_pac, comment]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 arch/arm64/kernel/stacktrace.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index a336cb1..b479df7 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -14,6 +14,7 @@
 #include <linux/stacktrace.h>
 
 #include <asm/irq.h>
+#include <asm/pointer_auth.h>
 #include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
 
@@ -101,6 +102,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
 	}
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
+	frame->pc = ptrauth_strip_insn_pac(frame->pc);
+
 	/*
 	 * Frames created upon entry from EL0 have NULL FP and PC values, so
 	 * don't bother reporting these. Frames created by __noreturn functions
-- 
2.7.4


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  parent reply	other threads:[~2020-02-17  9:31 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-17  9:27 [PATCH v5 00/17] arm64: return address signing Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 01/17] arm64: cpufeature: Fix meta-capability cpufeature check Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 02/17] arm64: cpufeature: add pointer auth meta-capabilities Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 03/17] arm64: rename ptrauth key structures to be user-specific Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 04/17] arm64: install user ptrauth keys at kernel exit time Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 05/17] arm64: create macro to park cpu in an infinite loop Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 06/17] arm64: add bootup/runtime flags for __cpu_setup Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 07/17] arm64: cpufeature: handle conflicts based on capability Amit Daniel Kachhap
2020-02-28 18:18   ` Catalin Marinas
2020-03-02  9:29     ` Amit Kachhap
2020-02-17  9:27 ` [PATCH v5 08/17] arm64: enable ptrauth earlier Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 09/17] arm64: initialize and switch ptrauth kernel keys Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 10/17] arm64: initialize ptrauth keys for kernel booting task Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 11/17] arm64: mask PAC bits of __builtin_return_address Amit Daniel Kachhap
2020-02-17  9:27 ` Amit Daniel Kachhap [this message]
2020-02-17  9:27 ` [PATCH v5 13/17] arm64: __show_regs: strip PAC from lr in printk Amit Daniel Kachhap
2020-02-17  9:27 ` [PATCH v5 14/17] arm64: suspend: restore the kernel ptrauth keys Amit Daniel Kachhap
2020-02-28 18:18   ` Catalin Marinas
2020-03-02 10:13     ` Amit Kachhap
2020-02-17  9:27 ` [PATCH v5 15/17] kconfig: Add support for 'as-option' Amit Daniel Kachhap
2020-02-17  9:39   ` Masahiro Yamada
2020-02-17 10:16     ` Vincenzo Frascino
2020-02-18  0:37       ` Masahiro Yamada
2020-02-18 10:14         ` Vincenzo Frascino
2020-02-17  9:27 ` [PATCH v5 16/17] arm64: compile the kernel with ptrauth return address signing Amit Daniel Kachhap
2020-02-28 18:23   ` Catalin Marinas
2020-03-02 10:19     ` Amit Kachhap
2020-03-02 13:16     ` Mark Brown
2020-03-04 11:01       ` Vincenzo Frascino
2020-03-03  9:28     ` Amit Kachhap
2020-03-04 10:53     ` Vincenzo Frascino
2020-02-17  9:27 ` [PATCH v5 17/17] lkdtm: arm64: test kernel pointer authentication Amit Daniel Kachhap

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